1. Field of the Invention
The present invention relates to a cartridge loading apparatus into which a disc cartridge is inserted and loaded into a prescribed position within the apparatus. The cartridge has a sliding shutter to expose a part of the disc.
2. Description of the Related Art
An optical disc apparatus which employs an optical disc as a storage medium for data has made possible a large increase in storage capacity compared with a magnetic disc loading apparatus. The optical disc apparatus can reproduce data in a stable manner with minimal noise. Further, in such an apparatus, extremely stable reproducing conditions are obtained, which substantially unaffected by external influences. Moreover, since the data processing is performed without physical contact between a recording/reproducing head and the surface of the optical disc, damage of the optical head and the optical disc are minimized. Therefore, the use of such optical disc apparatus has increased greatly.
With this trend of increased use of such an optical disc apparatus, there is now a strong demand for improved operability and for further measures to protect the optical disc, particularly during cartridge loading and unloading.
In this connection, an apparatus has been developed in which data can be processed with the disc inserted into the apparatus together with its cartridge. Thus there is no need to touch the optical disc directly with the hand. The cartridge generally has a shutter which closes when the disc is removed from the apparatus to protect the disc from damage or foreign substances.
In a conventional cartridge loading apparatus, as the disc cartridge is being inserted and loaded into its prescribed position within the apparatus, the shutter (which till then had remained shut) opens, to a position such that recording/reproducing can take place. Then, at a particular time, the optical disc starts to rotate and data is processed.
However, the conventional cartridge loading apparatus is not provided with any means of preventing the loading of the disc cartridge when, for some reason, the shutter of the cartridge does not open, or fails to open fully, as it is being loaded into its prescribed position within the apparatus.
In the conventional apparatus, therefore, when the shutter of the cartridge does not open, or fails to open fully, the shutter comes into contact with the motor, which rotates the disc, or with the recording/reproducing head. The disc motor is not likely to be damaged by this contact, but in the case of the recording/reproducing head, the possibility that substantial damage could be caused to the objective lens mounted at its top end, or to the precision elastic holder which retains the objective lens at the top end, constitutes a serious problem.